A typical packet-based communication network can support voice communication sessions between two or more participants. For example, the network could support a voice telephone call by transporting Internet Protocol (IP) packets between a calling party and a called party. One or more parties to the telephone call may notice echo occurring during the call. As an example, echo may occur when one party to the telephone call speaks into a mouthpiece of a telephone and the speaking party later hears his or her own voice in an earpiece of the telephone.